bulk acoustic wave (BAW)

The miniaturization of RF components and circuits is directly related to the miniaturization of mobile terminals. This requirement can be significantly realized by the Bulk Acoustic Wave (BAW) and Film Bulk Acoustic Resonator(FBAR) techniques based on mechanical bulk waves.

Both techniques are comparable, used in RF filters, resonators, MEMSresonators and duplexers, and are based on implanted silicon.

BAW technology is an integral part of the wafer process. As a result, BAW filters are extremely conductive and very small. They also achieve quality factors of over 1,000 and insertion losses that are below 0.5 dB per filter.

Bulk Acoustic Wave Filter (BAW) on a chip, Photo: Philips

BAW filters are available for frequency ranges from below 1 GHz up to about 20 GHz, i.e. for all mobile radio and wireless technologies.

BAW filter, photo: Philips

Compared to surface acoustic wave( SAW) filters, BAW filters feature improved power consumption and a better temperature coefficient, typically below 20 ppm/Kelvin. Compared to ceramic filters, they impress with much smaller dimensions.